/*
 * Copyright (c) 2010-2011, 2013, The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials provided
 *       with the distribution.
 *     * Neither the name of The Linux Foundation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
	Queue with Linked list
*/

#include "queue.h"
#include <stdio.h>
#include <stdlib.h>


Queue *alloc_queue()
{
	Queue *q = (Queue *) malloc(sizeof(Queue));
	if (q) {
		q->head = q->tail = NULL;
		q->current_size = 0;
	}
	return q;
}

void free_queue(Queue *q)
{
	while (q->current_size)
		pop(q);
}

void free_queue_and_qelement(Queue *q)
{
	while (q->current_size) {
		void *element = pop(q);
		if (element)
			free(element);
	}
}

int push(Queue *q, void * element)
{
	Node *new_node = (Node *) malloc(sizeof(Node));

	if (new_node == NULL)
		return -1;

	new_node->element = element;
	new_node->next = NULL;

	if (q->current_size == 0)
		q->head = new_node;
	else
		q->tail->next = new_node;

	q->tail = new_node;
	q->current_size++;
	//printf("Push Count = %d \n",q->current_size);

	return 0;
}

void *pop(Queue *q)
{
	Node *temp;
	void *element;

	if (q->current_size == 0)
		return NULL;

	temp = q->head;
	element = temp->element;

	if (q->current_size == 1)
		q->head = q->tail = NULL;
	else
		q->head = q->head->next;

	free(temp);
	q->current_size--;
	//printf("Pop Count = %d \n",q->current_size);
	return element;
}

